Combine like terms to create an equivalent expression. $1.3b+7.8-3.2b$
Combine the $\text{{coefficients}}$ of the $b$ terms. $\phantom{=}{{1.3}b+7.8{-3.2}b}$ $=\left({1.3}-{3.2}\right)\cdot b+7.8$ $=\left({-1.9}\right)\cdot b+7.8$ $=-1.9b+7.8$ The simplified expression is $-1.9b+7.8$